Transmission fluid check on 42RLE

RD3

TJ Enthusiast
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Feb 8, 2017
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Tullahoma, TN, United States
Just put a derale transmission cooler. Added a quart of fluid as directed. Do i check the level running, in gear or just hot but turned off?

I've also read that you can add extra fluid to 42rle and it wont hurt it? That true and why would you?

Sure wish I had an owner's manual
 
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Start the engine, then let the vehicle get up to operating temperature.

Next, shift through all the gears and finally put it in neutral with the engine still running. Now go check it!

You'll get a more accurate level check when it's in neutral since the transmission pump is working in neutral. The pump doesn't go on when it's in park.

I've heard of people with the 42RLE overfilling by as much as a quart without any issues. So I wouldn't feel uncomfortable slightly overfilling it, just don't go crazy.

IMPORTANT: Be sure to put the parking brake on (and be on a flat surface) when you're checking it in neutral. Either that, or have someone in the Jeep with their foot on the brake.

Oh, and here's all of the factory manuals, right here on this forum (thanks @JeepNWilly):
Jeep Wrangler TJ Factory Service Manuals (FSM) & Technical Documentation
 
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Well smack my butt Taylor Swift! Everything you need to know right here on this awesome forum. Hope i get to buy you guys a cold beverage some day

Haha, a lot of it is! If you ever get curious about something, browse through the TJ Frequently Asked Questions or TJ How-to Guides section. You might be surprised at what you find!
 
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Start the engine, then let the vehicle get up to operating temperature.

Next, shift through all the gears and finally put it in neutral with the engine still running. Now go check it!

You'll get a more accurate level check when it's in neutral since the transmission pump is working in neutral. The pump doesn't go on when it's in park.

I've heard of people with the 42RLE overfilling by as much as a quart without any issues. So I wouldn't feel uncomfortable slightly overfilling it, just don't go crazy.

IMPORTANT: Be sure to put the parking brake on (and be on a flat surface) when you're checking it in neutral. Either that, or have someone in the Jeep with their foot on the brake.

Oh, and here's all of the factory manuals, right here on this forum (thanks @JeepNWilly):
Jeep Wrangler TJ Factory Service Manuals (FSM) & Technical Documentation
Thank you. This was a tremendous help.
 
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That's true for the older 32RH but the 42RLE pump works in both Park and Neutral. :)

Yeah, I didn’t realize that until well after I posted. Good to know though as I’ve always been putting my 42RLE in neutral!